Restoring The Freshwater Pearl Mussel Population in the Upper River Moriston Glochidial Development Monitoring and Artificial Encystment.

Transcription

1 Restoring The Freshwater Pearl Mussel Population in the Upper River Moriston Glochidial Development Monitoring and Artificial Encystment.

2 Introduction to the River Moriston The River Moriston flows into the northern side of Loch Ness, the river and its main tributary, the river Loyne are regulated waters as part of a large scale SSE Hydro electric scheme, with dams at Dundreggan, Cluanie and a fish pass at Ceannocroc. Dundreggan Ceannocroc Cluanie

3 Historical records dating back to 1921 show evidence of pearl mussels throughout the river Pearl Fisher Neil McCormick reported pearl mussels occurred from Invermoriston up to Loch Cluanie Scottish National Pearl Mussel survey, 2000 Two live mussels and four empty shells were found in the upper river by SNH staff SNH commissioned a full detailed survey of the whole River Moriston. Mussels were found patchily distributed between Loch \ness and cluanie. Despite losses to pearl fishing and hydro- electric operations, the Moriston contained a viable or functional population and was considered to be of key importance to the survival of the species Further surveys revealed that only a few mussels were present in the upper Moriston

4 Value million European Funding 48 project actions 21 Natura sites throughout UK 22 partners - 14 Beneficiaries Physical delivery 8 co- financiers The Pearls in Peril LIFE+ Project

5 RESTORE Habitats for freshwater pearl mussels and host species Tackle diffuse pollution Riparian planting Reduce Nutrient input Encystment of juvenile salmonids SECURE Safeguard vulnerable populations Set up and promote riverwatch schemes Liaise with National wildlife crime unit and local police Liaise with water users, stakeholders and fisheries interests COMMUNICATE Pearls in the Classroom Local communities Project Dissemination

6 Baseline encystment surveys Glochidial development monitoring Juvenile encystment Post Encystment monitoring Pearls in the classroom Ness and Beauly Fisheries Trust What are we doing?

7

8 Baseline Encystment survey AIMS To determine if recruitment/encystment was actually taking place To determine which species and what size/age fish were being encysted. Method Electrofishing at sites where both juveniles and mussels are found. All fish examined Species and Length and numbers of visible glochidia recorded.

9 Number of fish Baseline encystment Survey Number of encysted fish Fish length

10 Glochidial Development Aims To determine glochidial release or Spat date Increase knowledge of larval development Methods Visual inspection of the gills Glochidia sample observed under x35 microscope Condition Description Pre Gravid Gills translucent, drab brown, with faint patches or streaks of pale brown/yellow (glochidia) Gravid Empty Gills translucent, drab brown, but completely or partly full of pale brown/cream/yellow/golden coloured glochidia Gills translucent, drab brown or grey-brown only Spent Gills shiny, dark green or green-brown gloss ( very distinct from normal colouration)

11 a) Stage 1 (age 4 days) b) Stage 2 (age 16 days) c) Stage 3 (age 23 days) d) Stage 4 (age 28 days) e) Stage 5 (age 30 days) Stage 1 Stage 2 Stage 3 Stage 4 Stage 5

12 Encystment Aim To restore the population in an area of low density Method Artificial Encystment. 1. Mussels induced to spat in bucket and returned 2. Glochidia transported to electrofishing site 3. Capture as many fish as possible Salmon and Trout of all sizes. 4. Record fish species/length and retain in bucket with glochidia. 5. Return encysted fish 6. Monitor site/fish following Autumn and Spring.

13 Electro fish encystment sites Record any encysted fish captured. Post Encystment Monitoring

14 Pearls in the classroom

15 Thanks for listening.